Flow cytometry is a powerful technology for cellular and subcellular analyses in biomedical research. Its primary power lies in its ability to rapidly perform multi-parametric analysis of individual cells, thereby permitting the identification and isolation of important subsets of cells. The Flow Cytometry Facility at The University of North Carolina at Chapel Hill was established in 1982 to provide this critical research core service. The Facility is the sole provider of research flow cytometry services to investigators at UNC-CH. The Facility currently has 3 analytical flow cytometers (2 FACScans, 1 FACSCalibur) and one sorter (MoFIo). The instruments are heavily used (last fiscal year 5,174.5 hours charged) and annually serve over 100 investigators. During the first 6 months of this fiscal year (July 1,2002 to Dec. 31, 2002) 2,699 hours have been charged to 81 investigators. A new major initiative in infectious diseases research at our institution has prompted a request that we move the existing FACSCalibur to a BSL-3 facility to provide infectious disease investigators the ability to perform flow cytometry on viable infectious samples. This would seriously interfere with our machine access time for general use and remove our ability to do 4-color analysis required by a growing group of investigators. Thus, we must replace the FACSCalibur before permitting this move. In addition, several investigators are requiring increased number of parameters (5+ colors), more and lower cost Ca++ mobilization experiments, excitation of CFP, and DNA content analysis using Hoechst or DAPI. Thus, in order to meet these increasing demands, replace the FACSCalibur's 4-color capability and general capacity, and provide for future developments we are requesting funds to purchase a four-laser, multi-parameter bench top analytical flow cytometer. At present, we believe the CyAn from DakoCytomation best fulfills our requirements and are requesting, in this application, the majority of funds to purchase the instrument. The University of North Carolina School of Medicine is providing $65,500 towards the purchase in addition to all installation/modification costs ($9,500). The School is also providing considerable on-going support towards the operation of The Flow Cytometry Facility - $80,000/year from The Uneberger Comprehensive Cancer Center and 25% of the Facility Director's salary from The Department of Microbiology and Immunology. [unreadable] [unreadable]